Personality traits as a possible factor in the inflammatory response in the first depression episode and in recurrent depressive disorders

Background and objectives: Depressive disorders are linked with an increase in the central and peripheral concentration of many pro-inflammatory cytokines, including mainly tumour necrosis factor alpha (TNF-alpha) and interleukins (ILs). The aim of the presented work is to verify whether personality traits predisposing to the occurrence of a depression episode are associated with changes in the peripheral expression of genes for selected cytokines. Methods: 77 individuals, who met the diagnostic criteria for a depression episode were qualified to take part in the study. Personality traits was measured using selected scales of The Minnesota Multiphasic Personality Inventory (MMPI-2). Expression at the mRNA and protein level for IL-1, IL-6, IL-10, IL-12 and TNF-alpha were examined. Results: A significant positive dependence was observed in the entire group examined with reference to the intensity of symptoms on the Welsh anxiety scale and the expression at the mRNA and protein level for the IL-12 gene. Analyses conducted separately for the first depressive episode group and the recurrent depression group revealed significant interrelations between the neurotic triad of the MMPI-2 test and the expression for genes IL-1, IL-10 and IL-12. Conclusions: (1) The intensity of depression episode symptoms, measured using the neurotic triad and the Welsh anxiety scale for the MMPI-2 test, correlate significantly with the expression at the mRNA and protein level for the genes of pro-inflammatory and anti-inflammatory cytokines. (2) Anxiety as a personality trait may be a significant marker of inflammation during a depression episode. (c) 2018 Asociacion Universitaria de Zaragoza para el Progreso de la Psiquiatria y la Salud Mental. Published by Elsevier Espana, S. L. U. All rights reserved.